Wildlife officials have confirmed a third livestock attack by the Snake River wolf pack in northeastern Oregon.

A rancher walking a fence line along the Imnaha River found an injured cow on Nov. 20, and it was examined by Oregon Department of Fish and Wildlife the following day. The cow had numerous bite wounds to its hind legs, according to a department news release.

The injuries were estimated to be 10 to 14 days old. Data from GPS tracking collars worn by pack members showed wolves of the Snake River pack were in the area during the estimated time of the attack. The pack attacked calves Oct. 16 and Nov. 4 in areas 2.5 and 4 miles north of the latest attack.

Gray wolves are protected under state and federal endangered species laws, but Oregon’s gray wolf management rules allows the ODFW to consider killing wolves in situations of “chronic livestock depredation.” One of the conditions is that a pack must have committed four confirmed and “qualifying” attacks on livestock within six months.

The Snake River pack now has three confirmed attacks on livestock, but so far only two have been counted as “qualifying” incidents. That determination typically is made within a few days of the initial confirmation, and is based in part on whether the rancher was taking action to deter wolves.

Wildlife managers have killed four wolves since the predators entered Oregon from Idaho in 1999. Two were shot in Baker County in 2009 after 29 animals, mostly sheep, were killed in a series of attacks; and two were killed in Wallowa County in 2011 after half a dozen head of cattle were killed in multiple incidents.